It took 10 years from the first state – Wisconsin – to the final states: Nevada, Alabama, Indiana and Louisiana. The Immune Deficiency Foundation, the Jeffrey Modell Foundation and other advocates championed the cause. The JMF had been tracking the state-by-state progress on a U.S. map.

John Boyle, who leads the Immune Deficiency Foundation, said that states don’t need to look far to find evidence that mandatory screening was the right choice. Children as old as 10 are “alive and thriving” thanks to early detection and treatment, he said. People who have SCID lack T cells, critical in the immune response to bacteria, viruses and other causes of infection.

Amy Walsh’s son, Aidan, has a milder form of SCID, but even so, the first five years of his life were rocky.

“Aidan's first illness resulted in his immune system attacking his hemoglobin when he was 10 months old,” she said. “By the time he was 4 years old, he had been diagnosed with eight different autoimmune diseases, had many hospitalizations – two that required extended stay in the ICU – for both autoimmune flares and various infections, unexplained fevers and pneumonia.”

The Walshes recently celebrated Aidan’s high school graduation and soon, he’s off to college. Amy Walsh said it’s hard to find the words to explain how happy she was to see all 50 states doing mandatory screening for SCID.

“Excited doesn't seem the appropriate word - ecstatic, elated, thrilled,” she said. “The fact that newborn screening for SCID is happening throughout the U.S. and that there are advocates determined to make the test standard procedure in countries around the world means lives are saved.”

Progress continues globally, according to the International Organisation for Immunodeficiencies (IPOPI). Countries already screening for SCID include Taiwan (2012), Israel (2015), Iceland (2017), New Zealand (2017) and Norway (2018). Germany and Sweden are expected to be next, a spokesperson for IPOPI said.

On a regional level, screening is also happening in parts of Italy, Canada, Australia and Spain, which reported last year that it had identified its first case of SCID and treated the infant. Research in Sweden and New Zealand showed that, in addition to alleviating suffering, the screenings were cost effective for health care budgets, according to IPOPI.

More screening is helping to reveal the true prevalence of the disease, IDF said. Ten years ago, experts believed one in 100,000 newborns tested positive for SCID. Today, the estimate is one in 40,000.